Problem: Express your answer as a mixed number simplified to lowest terms. $18\dfrac{1}{4}-8\dfrac{2}{3} = {?}$
Solution: Find a common denominator for the fractions: $= {18\dfrac{3}{12}}-{8\dfrac{8}{12}}$ Convert ${18\dfrac{3}{12}}$ to ${17 + \dfrac{12}{12} + \dfrac{3}{12}}$ So the problem becomes: ${17\dfrac{15}{12}}-{8\dfrac{8}{12}}$ Separate the whole numbers from the fractional parts: $= {17} + {\dfrac{15}{12}} - {8} - {\dfrac{8}{12}}$ Bring the whole numbers together and the fractions together: $= {17} - {8} + {\dfrac{15}{12}} - {\dfrac{8}{12}}$ Subtract the whole numbers: $=9 + {\dfrac{15}{12}} - {\dfrac{8}{12}}$ Subtract the fractions: $= 9+\dfrac{7}{12}$ Combine the whole and fractional parts into a mixed number: $= 9\dfrac{7}{12}$